Flick is optimistic about the possibility of midfielder Frenkie de Jong making a return as Barcelona aims to recover from two defeats in just 10 days, including losses to Monaco in the Champions League and Osasuna in La Liga.
The German coach has been dealing with an injury crisis, with key players such as Dani Olmo, Ronald Araujo, Gavi, and goalkeeper Marc-Andre ter Stegen unavailable.
In Saturday’s 4-2 loss to Osasuna, he opted to rest regular starters Lamine Yamal and Raphinha, prioritising the upcoming Champions League match.
De Jong, who has been sidelined since April with an ankle injury, also missed the European Championship while focussing on his recovery.
“We will play with the team we believe to be the best in order to beat Young Boys. The first game (at Monaco) we lost, yes. But we must not be depressed,” Flick told reporters.
“We have to recover our balance after the defeat at Osasuna. We have to build the game with fewer mistakes. Responsibilities must be assumed.
“We need fresh legs, and Frenkie’s return is great news. Even if it’s just for five or 10 minutes. If he gets the chance, he’ll play.”
Flick previously said his choice to rest key starters affected the team in their first domestic loss of the season at Osasuna, ending a seven-game winning streak.
Young Boys will arrive in Spain following a 3-0 defeat by Aston Villa in their opening Champions League match at home.
Asked if the five-times European Cup winners have lost respect after their defeat at Monaco, Flick said: “I am positive we can win… we play good football – entertaining football. And if we need to gain the respect of our opponents once again, we’re going to work hard on that.”